Debouncing is a performance optimization technique that limits how often a function can execute. It delays function execution until after a certain amount of time has passed since the function was last called. Imagine a user typing in a search box - instead of making an API call on every keystroke, debouncing waits until they pause typing.

The key insight with debouncing is that we reset the timer every time the function is called. Only when the user stops calling the function for the specified delay does the actual execution happen. This is perfect for events that fire rapidly but where you only care about the final state.